Conventional systems and methods of projecting images onto flat display surfaces are well-known. In the most simple example, a projector is positioned at a desired distance from a flat display surface so that the projector is substantially normal to the surface (i.e., the projection angle is normal to the display surface). Suitable flat surfaces often include movie screens, walls, ceilings, etc. Because the projection angle is substantially normal to the display surface, and because the display surface is substantially flat, projected images will not experience significant optical distortion.
The projection of images onto more complex surfaces, such as curved, angled, or adjoining non-coplanar surfaces, is also known. Conventional projection systems and methods, however, can not project images onto such surfaces without substantial optical distortion of the image. When a conventional projection system/method is used to project images onto such complex surfaces, optical distortion of the image results from the projection angle being other than normal for at least a portion of the display surface. Thus, distortion of the projected image is perceived when conventional projection systems/methods are used to project onto adjacent walls, adjacent walls and ceilings, non-planar surfaces, non-coplanar surfaces, curved surfaces, or the like. Thus, conventional projection systems/methods are limited to projecting images on display surfaces where the projection angle is normal to the display surface and the display surface is substantially flat.
In order to compensate for the optical distortion resulting from the projection angle being other than normal to the display surface and/or the display surface being other than flat, advanced projections techniques and systems have been developed to compensate for these optical distortion problems (such as those projections systems used to project images onto broad, curved screens, such as in IMAX theaters). Existing projection systems address the distortion problem through digital manipulation techniques that alter the dimensions of the still images or video. One such digital manipulation technique that is well known in the art is that of “keystoning.”
During a keystone digital correction technique, the dimensions of the image to be projected onto the display surface are altered so that the image appears distorted prior to projection, often into the shape of a keystone. When the distorted image is then projected onto an angled display surface (or at a projection angle other than normal), the image appears undistorted on the display surface from the viewer's perspective.
Such projection systems are limited in direction, area of projection, and the number of surfaces or objects within the area of projection upon which an image is capable of being displayed. Moreover, many such systems must be manually manipulated as an initial step in order to allow for the projection image to be seen on adjacent walls without the appearance of distortion. Furthermore, such systems are limited in that they can only project on adjacent surfaces, e.g., wall and adjacent wall, wall and adjacent ceiling, or the like. Such systems cannot project images onto multiple non-contiguous and/or non-adjacent surfaces within a three-dimensional area. In order to accomplish the projection of images on multiple non-contiguous and/or non-adjacent surfaces, multiple projection devices must be employed.
Finally, it is not known to project continuous video images onto adjacent walls or flat screens joined at corners. Home, office and theater projection is currently limited to single contiguous surfaces, because images cannot be projected onto adjacent walls or onto walls and ceilings without distortion. Thus, there is a need for coordinated projection of video or digitized film simultaneously onto multiple surfaces joined at corners.